Cutter chain

ABSTRACT

A cutter chain employing pintles having end portions nonrotatively retained within cutter carrying links and having a recessed central portion along one side to allow space for greater than normal sprocket tooth size relative to a given pitch length.

United States Patent Glenn 8. McDowell 601 Wiley Ave., Franklin, Pa. 16323 812,758

Apr. 2, 1969 June 22, 1971 Inventor Appl. No. Filed Patented CUTTER CHAIN 9 Claims, 5 Drawing Figs.

US. Cl 74/254 lnt.Cl F16g 13/04 Field of Search 74/250,

[56] References Cited UNITED STATES PATENTS 2,788,670 4/ 1957 Bruestle 74/251 2,826,085 3/1958 Cartlidge 74/254 2,956,442 10/1960 Krekeler.... 74/254 3,086,404 4/l963 Krekeler 74/254 Primary Examiner- C. .l. H usar Attorney-15. Wallace Breisch ABSTRACT: A cutter chain employing pintles having end portions nonrotatively retained within cutter carrying links and having a recessed central portion along one side to allow space for greater than normal sprocket tooth size relative to a given pitch length.

PATENTEnJunezlsn 3,585,872

2a'\\\L 24 2a 4x16 2/ 29' 35 F ig. E

INVENTOR. Glenn 5. McDowell.

CUTTER CHAIN The present invention relates to cutter chains such as those used in coal cutters and ripper chain mining machines, which chains are made up of a plural of saddle-type bit carrying links alternating with and connected together by insertion-type connector links. All of said links being flexibly attached to adjacent links by pintles nonrotatively held in a bit link and rotatively engaged by adjacent connector links. The cutter chains of this invention are quite similar to those shown and described in U.S. Pat. No. 2,956,442 (Krekler).

The cutter chain of this invention is of novel design giving rise to the following advantages:

The pintle of this invention being provided with a recessed central surface portion comprising a pair of bearing surfaces having separate axes has, compared to prior art pintles, and additional contact area when the chain is first installed and operated;.

Because of the additional contact area the cutter chain of this invention has less likelihood of seizing and galling occurring between the pintles and the connector links and consequently the first operation of the cutter chain of this invention is safer and can be faster and more prolonged than similar prior art chains.

These and other advantages and objects of this invention will become more readily apparent upon consideration of the following description and drawings in which:

FIG. 1 is a three-dimensional oblique view at approximately full size of a pintle constructed according to the principles of this invention;

Fig. 2 is a sectional view taken substantially on line 2-2 of Fig. l;

FIG. '3 is a smaller scale, side elevational view of a portion of a cutter chain constructed according to the principles of this invention;

FIG. 4 is a sectional view taken substantially on line 4-4 of FIG. 3;

FIG. 5 is an enlarged fragmentary sectional view taken substantially on line 5-5 of FIG. 4.

Referring now to the drawings, FIG. 3 shows a portion of a cutter chain comprising a plurality of cutter bit links 12 and connector links 14 flexibly fastened together by pintles 16 to form a flexible chain in a manner well-known in the art. The bit links 12 are provided with bit receiving sockets (not shown) and suitable bit fastening means such as set screws (also not shown) in a well-known manner. The bit links 12 are of the saddle type having at each end thereof a pair of cheeks 13 spaced apart to receive one end of a connector 14 between the cheeks 13 at either end of the bit link 12. The pair of cheeks 13 at one end of a bit link 12 have respective coaxial openings 18 therein of noncircular outlines shown as D- shaped with a flat surface 19 on the side of the opening nearest the transverse center line of the respective link.

Extending through the cheek means 18 and slidably received therein are the pintles 16 having D-shaped end portions 20 of the same shape as the cheek openings 18 and preferably sized to be a driving fit in the cheek openings 18 so that the pintles 16 are nonrotatively retained by the cheeks 13 due to the noncircular nature of the cheek openings 18 and the driving fit of the pintle in the openings 18. The D-shaped end portions 20 have major surface portions 20' of circularly curved outline (portions of circular cylindrical surfaces) centered on an axis 16 which extends through the centers of curvature of both end surface portions 20 and is considered to be the central axis of the pintle 16. The remainder of the surfaces of the end portions 20 comprises flat surfaces 21 best described as forming the exterior surface of a common sector of the pintle 16 so that the two flats are coplanar and equidistant from the axis 16 in a given direction.

The central portion 24 of the pintle 16 has three surface portions as hereinafter described. A surface portion 24 amounting to approximately one-half of the surface of the central portion 24 (to the left as seen in FIGS. 1 and 2) is simply a coaxial continuation of the circular portions 20 of the end surface portions 20 as earlier described, all portions of the surface portion 24. being equidistant from the common axis 16'. The remainder of the surface of the central portion 24 comprises upper and lower recessed curved portions 28 and 29, respectively, along one side of the pintle 16 which are formed on a radius approximately equal to, or slightly smaller than the radius of circular portions 20 of the end portions 20 and are portions of two separate intersecting cylindrical surfaces having spaced apart axes indicated as 28' and 29' parallel to axis 16' (see F IG. 5). The axis 28 to the left and somewhat above the central axis 16 of the pintle 16 is the axis of surface 28 while the axis 29' of the lower surface 29 is to the left and somewhat below the central axis 16 of the pintle 16 as seen in FIG. 5. To further locate the surfaces 28 and 29 it will be seen that the surface 28 is in the same quadrant relative to the axis 16' as the upper line of intersection between the flat surface 21 and the curved surface 20' of the end surface portion as seen in FIG. 1 while the lower surface 29 is in the same quadrant as the lower line of intersection between the surfaces 21 and the curved surfaces 20'. It is further to be noted that the surfaces 28 and 29 intersect along a line 30 equidistant from and parallel to the axes 28' and 29. The surfaces 28 and 29 can be described as being the exterior surface of a sector of the pintle 16 having a central angle of about 180 as seen in FIG. 2. The extent of this pair of surfaces can vary throughout a range between and l95 though preferably about as shown. The formation of the surfaces 28 and 29 develops inwardly facing shoulders 27 between the end portions 20 and the respective surfaces 28 and 29. The utility of this three-part surface will be made plain in conjunction with the following description.

Each end of the connector 14 is provided with a circular bore 31 of substantially the same diameter as the circular portion 20' of the end portion 20 but enough larger to provide clearance for a sliding fit of the end portion 20 through the connector bore 31. Thus, when the connector end is between the cheeks l3 and the openings 18 are aligned with the bore 31 a pintle 16 can be inserted through one of the openings 18, through the connector bore 31 and the other opening 18 to assemble a connector link with a bit link 12 in a known manner. Once this assembly has been accomplished the normal tension of the chain, wherever installed, will cause the connectors 14 to move apart (to the left as seen in FIG. 5) bringing each connector 14 and the respective pintle 16 into the relationship there shown. The axial length of the recessed surface portions 28 and 29 being slightly greater than the thickness of the connector 14 will allow the connector 14 to move into the position shown. As seen in FIG. 5 the connector bore 31 will very nearly fit the right-hand half of the surface of the pintle central portion 24 but it is to be noted that due to the displacement of the centers of the upper and lower curved portions 28 and 29 there will be, in newly installed pintles and connectors, two narrow areas of contact in the positions indicated at 34 and 35 upper right and lower right portions of bore 31, respectively, as viewed in FIG. 5. The usefulness of this type of new component fit will be obvious to those familiar with the cutter chain art since it is well known that however carefully pintles and connectors are manufactured there is only a single line or very narrow area of contact between the pintle surface and the connector bore in a new chain. With such a narrow area of contact the unit pressures have been very high during the first period of chain operation using new components with the result that some of the pressures reach values which will cause welding of the two surfaces which must move relative to each other. As is well known the result of such welding is transfer of metal from one surface to the other with consequent scoring and galling of these surfaces leading to pin seizure and premature pintle or connector failure and other damaging results. With the two areas of contact developed by the double axis shape of the central portion 24 with respect to connector bore 31 in the structure of the instant invention it is obvious that the pressures will be of approximately one-half the amount found in the use of simple cylindrical pintles with a cylindrical bore as specified in the prior art or even a recessed pin with a single axis contact surface. The result is that the likelihood of seizing and galling is greatly reduced with the pintle of the present invention.

it is to be realized that although the three-surface central portion of this invention has been described with the recess surfaces on the same side as the flat area of the end portion at least some of the advantages inherent in the three-surface central portion of this invention could be realized with the end surface portion flat in a different relationship to the recess surface and indeed the three surface central portion could be used with any noncircular end portions without departing from the scope of this invention.

A preferred embodiment of this invention having been hereinabove described it is to be realized that variations in the application of the principles of this invention can be applied without departing from the principles of this invention. It is therefore respectfully requested that this invention be interpreted as broadly as possible.

What I claim is:

l. A pintle comprising: a body member having axially spaced end portions and a central portion intermediate said end portions, said central portion having a recessed exterior surface extending axially thereof along one side thereof; said recessed surface being formed from portions of two separate intersecting cylindrical surfaces of substantially equal radius having spaced apart axes parallel to the central axis of the pintle and substantially equidistant therefrom.

2. A pintle as specified in claim 1 wherein said recessed surface subtends a dihedral angle of between and 195.

3. A pintle as specified in claim 1 wherein said recessed surface subtends a dihedral angle of substantially 43. A pintle as specified in claim 1 wherein the distance between the spaced axes of said separate cylindrical surfaces is less than the distance of said spaced axes from said central axis.

5. A pintle as specified in claim 4 wherein the end portions of said pintle have at least major surface portions of circular cylindrical shape and said two separate cylindrical surfaces of said recessed surface have equal radii approximately equal to the radius of said end surface major portions.

6. A pintle as specified in claim 5 wherein said end portions have flat surfaces forming the surface of a common sector of said pintle.

7. A pintle as specified in claim 6 wherein a plane containing said central axis and the line of intersection of said two separate cylindrical surfaces is substantially normal to said flat surfaces.

8. A pintle as specified in claim 6 wherein said recessed surface includes said common sector of said flat surfaces.

9. A cutter chain pintle as specified in claim 11, inserted through each set of said aligned openings in said overlapped end portions of said links. 

1. A pintle comprising: a body member having axially spaced end portions and a central portion intermediate said end portions, said central portion having a recessed exterior surface extending axially thereof along one side thereof; said recessed surface being formed from portions of two separate intersecting cylindrical surfaces of substantially equal radius having spaced apart axes parallel to the central axis of the pintle and substantially equidistant therefrom.
 2. A pintle as specified in claim 1 wherein said recessed surface subtends a dihedral angle of between 165* and
 195. 3. A pintle as specified in claim 1 wherein said recessed surface subtends a dihedral angle of substantially 180*.
 4. A pintle as specified in claim 1 wherein the distance between the spaced axes of said separate cylindrical surfaces is less than the distance of said spaced axes from said central axis.
 5. A pintle as specified in claim 4 wherein the end portions of said pintle have at least major surface portions of circular cylindrical shape and said two separate cylindrical surfaces of said recessed surface have equal radii approximately equal to the radius of said end surface major portions.
 6. A pintle as specified in claim 5 wherein said end portions have flat surfaces forming the surface of a common sector of said pintle.
 7. A pintle as specified in claim 6 wherein a plane containing said central axis and the line of intersection of said two separate cylindrical surfaces is sUbstantially normal to said flat surfaces.
 8. A pintle as specified in claim 6 wherein said recessed surface includes said common sector of said flat surfaces.
 9. A cutter chain pintle as specified in claim 1, inserted through each set of said aligned openings in said overlapped end portions of said links. 